• Nuclear Engineering and Technology
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• 제51권2호
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• pp.345-355
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• 2019

Use of the reconstructed fuel assemblies from partially burnt nuclear fuel pins is analyzed. This reutilization option is a potential candidate technique to make better use of the nuclear resources. Standard two step method is used to calculate node i.e. fuel assembly average burnup and then pin by pin ${\eta}$ values are reconstructed to ascertain the residual reactivity in the used fuel pins. Fuel pins with ${\eta}$ > 1:0 are used to reconstruct to-be-reused fuel assemblies. These reconstructed fuel assemblies are burnt during the cycle 3, 4, 5 and 6 of a 1000 MW PWR core by replacing fresh, once burnt and twice burnt fuel assemblies of the reference core configurations. It is concluded that using reconstructed fuel assemblies for the fresh fuel affect dearly on the cycle length (>50 EFPD) when more than 16 fresh fuel assemblies are replaced. However, this loss is less than 20 days if the number of fresh fuel assemblies is less than eight. For the case of replacing twice burned fuel, cycle length could be increased slightly (10 days or so) provided burnt fuel pins from other reactors were also available. Reactor safety parameters, like axial off set (< ${\pm}10%$), Doppler temperature coefficient (<0), moderator temperature coefficient at HFP (<0) are always satisfied. Though, 2D and 3D pin peaking factors are satisfied (<1:55) and (<2:52) respectively, for the cases using eight or less reconstructed fuel assemblies only.

• 에너지공학
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• 제25권4호
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• pp.198-206
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• 2016

자동차 표시연비는 국가적으로 에너지관리 지표로서 활용되며, 자동차 제작사의 기술개발을 유도하고, 소비자 차량구매 시 정보제공의 역할을 담당하고 있다. 하지만 정부의 표시연비가 체감연비와 상이하다는 소비자 불만이 지속되어 정부는 보다 정확한 표시연비 측정을 위해 미국의 5-cycle 시험방법을 국내 차량 기준에 맞게 재설정하여 도입하였다. 본래는 다양한 환경조건 및 주행패턴이 반영된 5개의 시험모드를 모두 주행함으로써 측정된 결과 값을 표시연비로 계산하는 방법이지만 소요되는 자원의 급격한 증가에 따른 충격을 완화하기 위하여 2개의 시험모드(도심(FTP-75 mode), 고속도로(HWFET mode))의 결과 값을 5-cycle 시험법으로 계산된 연비 값과 동등한 수준으로 산출하는 5-cycle 보정식을 사용하고 있다. 이 보정식은 2011년에 30대 차량의 5-cycle 시험방법으로 산출되었으나 최근 자동차 기술의 급속한 발전으로 인한 신형식 자동차에 대한 기존 5-cycle 보정식에 대한 검토가 필요할 것으로 판단되었다. 본 연구에서는 최근 기술이 적용된 14대의 신형식 자동차를 대상으로 기존과 동일한 시험 방법을 통해 시험모드별 연비 특성을 확인하고, 기존에 개발된 보정식과 차이를 분석한 결과 기존 시험 차량 결과와 큰 차이를 보이지 않았으며 보정식 또한 최대 1.5% 이내의 오차로써 기존 연비 보정식은 현재의 자동차 기술발전에 따른 개선도에 크게 영향을 받고 있지 않음을 알 수 있었다.

• 방사성폐기물학회지
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• 제19권4호
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• pp.435-446
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• 2021

This article examines the consequences of a significant spent fuel management decision or event in the United States, South Korea and Taiwan. For the United States, it is the financial impact of the Department of Energy's inability to take possession of spent fuel from commercial nuclear power companies beginning in 1998 as directed by Congress. For South Korea, it is the potential financial and socioeconomic impact of the successful construction, licensing and operation of a low and intermediate level waste disposal facility on the siting of a spent fuel/high level waste repository. For Taiwan, it is the operational impact of the Kuosheng 1 reactor running out of space in its spent fuel pool. From these, it draws six broad lessons other countries new to, or preparing for, nuclear energy production might take from these experiences. These include conservative planning, treating the back-end of the fuel cycle holistically and building trust through a step-by-step approach to waste disposal.

• Nuclear Engineering and Technology
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• 제43권2호
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• pp.141-148
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• 2011

This paper presents the quantitative analysis results of research on the burnup effect on the nuclear fuel cycle cost of BeO-$UO_2$ fuel. As a result of this analysis, if the burnup is 60 MWD/kg, which is the limit under South Korean regulations, the nuclear fuel cycle cost is 4.47 mills/kWh at 4.8wt% of Be content for the BeO-$UO_2$ fuel. It is, however, reduced to 3.70 mills/kWh at 5.4wt% of Be content if the burnup is 75MWD/kg. Therefore, it seems very advantageous, in terms of the economic aspect, to develop BeO-$UO_2$ fuel, which does not have any technical problem with its safety and is a high burnup & long life cycle nuclear fuel.

• 한국유체기계학회 논문집
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• 제15권3호
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• pp.57-63
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• 2012

Effects of coolant pre-cooling and fuel pre-heating on the performance of a combined cycle using a F-class gas turbine were investigated. Coolant pre-cooling results in an increase of power output but a decrease in efficiency. Performance variation due to the fuel pre-heating depends on the location of the heat source for the pre-heating in the bottoming cycle (heat recovery steam generator). It was demonstrated that a careful selection of the heat source location would enhance efficiency with a minimal power penalty. The effect of combining the coolant pre-cooling and fuel pre-heating was also investigated. It was found that a favorable combination would yield power augmentation, while efficiency remains close to the reference value.

• Nuclear Engineering and Technology
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• 제8권4호
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• pp.219-229
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• 1976

우리나라에서 건설될 가상적인 1125MWe PWR발전소에 대해 통계적인 방법으로 몇가지 서로 다른 핵주기간의 상호 경제성을 살펴 보았다. 모든 핵연료 파라메타들은 각기 적절한 확률분포함수를 갖고 있는 통계적인 변수로 취급하였고, 무작위 표본 추출 방법으로 요구비용 및 여러가지 핵주기성분에 대한 break-even 코스트들의 히스토그램을 얻었다. 이 히스토그램으로 throw-away 주기에 대한 재처리 및 플루토늄 재장전주기의 cost-benefit를 조사하였다.

• Nuclear Engineering and Technology
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• 제39권6호
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• pp.683-690
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• 2007

Because of increasing concerns regarding global warming and the longevity of oil and gas reserves, the importance of nuclear energy as a major source of sustainable energy is gaining recognition worldwide. To make nuclear energy truly sustainable, it is necessary to ensure not only the sustainability of the fuel supply but also the sustained availability of waste repositories, especially those for high-level radioactive waste (HLW). From this perspective, the effort to maximize the waste loading density in a given repository is important for easing repository capacity problems. In most cases, the loading of a repository is controlled by the decay heat of the emplaced waste. In this paper, a comparison of the decay heat characteristics of HLW is made among the various fuel cycle options. It is suggested that, for a future fast breeder reactor (FBR) cycle, the removal and burning of minor actinides (MA) would significantly reduce the heat load in waste and would allow for a reduction of repository size by half.

• 공학기술논문지
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• 제6권2호
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• pp.125-129
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• 2013

In the pyrochemcial process of spent nuclear fuel, it is necessary to separate rare earth nuclides from LiCl-KCl eutectic waste salt for radioactive waste reduction. This paper presents the phosphorylation of neodymium chloride in LiCl-KCl-NdCl₃ system using Li₃PO₄-K₃PO₄ as a phosphorylation agent in a chemical reactor with pitched blade impellers. The phosphorylation test was performed changing operation temperature, stirring rate, and amount of phosphorylation agent. Neodymium chloride was effectively converted into neodymium phosphate (NdPO₄). It was confirmed that more than 99 wt% of neodymium can be separated from LiCl-KCl-NdCl₃ system using a phosphorylation method l

• 방사성폐기물학회지
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• 제13권4호
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• pp.243-251
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• 2015

국내 원자력발전은 현재 두 번째로 큰 전력 공급 방법이며 원전의 수 역시 증가되는 것으로 계획되어 있다. 그러나, 원자력발전에 의해 발생되는 사용후핵연료에 대해서는 아직 명확한 관리 정책이 확립되어 있지 않다. 원자로 이 후 핵물질 흐름과 관련된 후행 핵연료주기는 사용후핵연료 관리를 위한 기술들의 집합이다. 따라서, 사용후핵연료 관리 정책은 핵연료주기 선택과 함께한다. 핵연료주기 선택의 중요 항목은 경제성으로 이는 사적비용과 함께 외부비용을 더해 결정되어야 한다. 직접비용 인 사적비용과 달리 간접비용인 외부비용에 대한 연구는 원전에 집중되어 있으며 핵연료주기에 대한 연구는 없는 상황이다. 본 연구에서는 핵연료주기에 적용할 수 있는 외부비용 항목들을 도출하고 정량화를 시도하였다. 핵연료주기 외부비용 평가를 위해 고려될 수 있는 핵연료주기로 OT(직접처분), DUPIC(PWR-CANDU 연결), PWR-MOX(PWR 습식재처리), Pyro-SFR (파이로 처리와 고속로 연계)의 네 가지를 선정하였다. 원자력발전의 외부비용 평가에 고려되었던 항목들을 분석하여 핵연료주기에서 에너지 공급 안보비용, 사고위험비용과 수용성 비용을 외부비용 항목으로 도출하고 추산하였다.

• Journal of Radiation Protection and Research
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• 제28권4호
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• pp.361-368
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• 2003

The economic and environmental friendliness analysis of the nuclear fuel cycle options that can be expected in Korea were performed. Options considered are direct disposal, reprocessing and DUPIC (Direct Use of Spent PWR Fuel In CANDU Reactors). By considering the result of calculation of the annual uranium requirement and nuclear spent fuel generation by analysis of nuclear fuel material flows in the nuclear fuel cycle options, we decided the time of back-end nuclear fuel cycle processes and the volume. Then we can analyze the economic and environmental friendliness by applying the unit cost and unit value of each process, respectively.